Heat-treatment-free anti-deformation construction process for C-shaped liquid tank deep-well pump base

Abstract

The invention relates to the field of liquid tank construction processes, in particular to a C-shaped liquid tank deep-well pump base heat-treatment-free anti-deformation construction process which comprises the steps of prefabricating a stainless steel deep-well pump base, completing pre-welding and heat treatment of a C-shaped liquid tank body and assembling and fixing the base. The low-temperature steel deep-well pump base made of the same material as the tank body is replaced by stainless steel, the base is thoroughly separated from a high-temperature heat treatment environment by utilizing the characteristic that stress relief heat treatment does not need to be carried out on the low-temperature steel tank body through stainless steel, and the problems of material microstructure change and thermal expansion and cold contraction caused by high-temperature annealing are avoided; the condition that the planeness of the flange surface of the base and the coaxiality of the spigot are reduced is fundamentally avoided; through the mode that the high-precision stainless steel base is prefabricated and the tank body is directly assembled after heat treatment, the machining procedure after deformation is omitted, and cost reduction, efficiency improvement and service life prolonging are achieved while the assembly precision and the structural stability of the tank body are guaranteed.

Description

A heat-free, deformation-resistant construction process for C-type liquid tank deep well pump base Technical Field

[0001] This invention relates to a heat treatment process, and more particularly to a heat treatment-free, deformation-resistant construction process for a C-type liquid tank deep well pump base, belonging to the field of liquid tank construction technology. Background Technology

[0002] Existing C-type liquid tanks made of low-temperature steel must undergo overall stress-relieving heat treatment, including the tank body and outfitting components of the same material, in order to eliminate residual welding stress and restore the toughness of the base material, according to welding process specifications and material certification requirements.

[0003] However, existing technologies have the following significant drawbacks: First, heat treatment can lead to uncontrollable structural deformation. Deep well pump base flanges are usually made of the same material as the tank body and need to be heat-treated in the furnace along with the tank body. The high-temperature annealing process can cause changes in the microstructure of the material and thermal expansion and contraction, resulting in a serious decrease in the flatness of the base flange surface and the coaxiality of the stop. Second, the amount of deformation caused by heat treatment is often uneven, requiring machining to match the dimensions of the deep well pump, which makes structural repair more difficult. In order to solve the structural deformation problem, traditional processes require large-area correction and fitting processes after heat treatment, and even secondary machining on site, which leads to a surge in labor costs and an extension of the construction cycle.

[0004] Therefore, it is urgent to improve the heat treatment process of the C-type liquid tank deep well pump base to solve the above-mentioned problems. Summary of the Invention

[0005] The purpose of this invention is to provide a heat-free, deformation-resistant construction process for C-type liquid tank deep well pump bases. This process involves replacing the cryogenic steel deep well pump base, which is made of the same material as the tank body, with stainless steel. By utilizing the characteristic that stainless steel does not require stress-relieving heat treatment along with the cryogenic steel tank body, the base is completely removed from the high-temperature heat treatment environment. This avoids changes in the material's microstructure and thermal expansion and contraction caused by high-temperature annealing, and fundamentally eliminates the decrease in the flatness of the base flange surface and the coaxiality of the stop.

[0006] To achieve the above objectives, the main technical solution adopted by this invention includes: a heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base, comprising the following steps:

[0007] S1. Prefabricated deep well pump base: The deep well pump base is fabricated. The flanges and connecting structures on the deep well pump base are machined according to the installation accuracy requirements of the deep well pump. After passing the accuracy test, it is ready for use.

[0008] S2. Complete the pre-welding and heat treatment of the C-type liquid tank body: Use a suitable C-type liquid tank body, on which a base installation position for installing the deep well pump base is provided. Weld a low-temperature steel pad of the same material as the C-type liquid tank body. Complete the welding construction of all pre-welded parts of the C-type liquid tank body. Heat treat the C-type liquid tank body after the pre-welding construction to eliminate the residual stress after the welding construction of the C-type liquid tank body. After the heat treatment is completed, perform non-destructive testing on the C-type liquid tank body to confirm its quality is qualified.

[0009] S3. Base Assembly and Fixing: After the C-type liquid tank body is heat-treated, the base installation station is cleaned, positioned and leveled. After verifying the installation benchmark, the prefabricated qualified deep well pump base is hoisted to the designated installation position. The levelness and coaxiality of the deep well pump base are adjusted to meet the assembly requirements. After positioning, the deep well pump base is welded and fixed to the pad, and the weld quality is inspected.

[0010] Preferably, in step S1, after the deep well pump base is machined, it is subjected to surface treatment. The machining accuracy must ensure that the flatness of the flange surface and the coaxiality of the stop of the deep well pump base meet the direct assembly requirements of the deep well pump.

[0011] Preferably, in step S2, when welding the pad, a vent hole is reserved on it, and the vent hole is temporarily protected. The vent hole is not welded and sealed during the construction of the C-type liquid tank body, and the temporary protection is removed after the construction of the C-type liquid tank body is completed.

[0012] Preferably, all outfitting components on the C-type liquid tank body, except for the pre-welded backing plate, are not directly welded to the tank base material before the tank body is heat treated.

[0013] Preferably, in step S3, the heat treatment of the C-type liquid tank body includes the entire process of furnace heating, heat preservation and air cooling of the C-type liquid tank body, and the heat treatment process parameters meet the welding process specifications and material certification requirements of the low-temperature steel tank body of the C-type liquid tank body.

[0014] Preferably, in step S4, the deep well pump base is positioned using a measuring tool, and its levelness and coaxiality are monitored in real time during the adjustment of the deep well pump base to ensure that the installation and fitting accuracy of the deep well pump base and the deep well pump are matched.

[0015] Preferably, in step S4, the weld quality inspection between the deep well pump base and the pad plate is carried out using a non-destructive testing method to ensure that the weld quality meets the requirements of the welding process specifications.

[0016] Preferably, after step S4 is completed, the subsequent construction procedures of the C-type liquid tank body are continued, including the installation of other outfitting components and piping systems, water pressure testing, insulation construction, and cleaning and sealing, until the overall construction of the C-type liquid tank body is completed.

[0017] Preferably, the main body of the C-type liquid tank is made of cryogenic steel; the base of the deep well pump is made of stainless steel.

[0018] Preferably, step S1 and step S2 are parallel steps.

[0019] This invention has at least the following beneficial effects:

[0020] 1. By replacing the cryogenic steel deep well pump base, which is made of the same material as the tank body, with stainless steel, the base is completely removed from the high-temperature heat treatment environment, taking advantage of the fact that stainless steel does not require stress-relieving heat treatment along with the cryogenic steel tank body. This avoids changes in the material's microstructure and thermal expansion and contraction caused by high-temperature annealing, fundamentally eliminating the decrease in the flatness of the base flange surface and the coaxiality of the stop. By prefabricating high-precision stainless steel bases and directly assembling the tank body after heat treatment, the machining process after deformation is eliminated. While ensuring assembly accuracy and tank structure stability, this method also reduces costs, increases efficiency, and extends service life. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 is a flowchart of the heat treatment process provided by the present invention;

[0023] Figure 2 is a three-dimensional structural diagram of the C-type liquid tank provided by the present invention;

[0024] Figure 3 is a side view of the main body of the C-type liquid tank provided by the present invention;

[0025] Figure 4 is a schematic diagram of the deep well pump base provided by the present invention.

[0026] In the diagram, 1. Type C liquid tank body; 2. Deep well pump base; 3. Deep well pump; 4. Pad plate. Detailed Implementation

[0027] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0028] As shown in Figures 1-4, the heat treatment process for the C-type liquid tank deep well pump base provided in this embodiment includes the following steps:

[0029] Prefabrication of Deep Well Pump Base 2: The integrated deep well pump base 2 is fabricated in the workshop using stainless steel. High-precision CNC machining tools are used to machine the flanges and connecting structures on the deep well pump base 2 according to the installation accuracy requirements of the deep well pump 3. The machining accuracy must ensure that the flatness of the flange surface and the coaxiality of the stop of the deep well pump base 2 meet the direct assembly requirements of the deep well pump 3 to avoid subsequent secondary corrections. Then, high-precision testing instruments, such as a level or coaxiality tester, can be selected according to the working conditions without limitation, to perform full-dimensional testing of the form and position tolerances of the base. After passing the accuracy test, it is ready for use.

[0030] The stainless steel material of the deep well pump base 2 can be 304L, 316L or 316H type austenitic stainless steel. This series of materials has excellent low temperature toughness, corrosion resistance and weldability. The specific material can be selected according to the working conditions and there is no limitation. After the deep well pump base 2 is machined, it is surface treated. Specifically, the entire deep well pump base 2 is subjected to surface rust removal and passivation treatment to form a corrosion-resistant surface protective layer.

[0031] Complete the pre-welding and heat treatment of the C-type liquid tank body 1: The C-type liquid tank body 1 is made of low-temperature steel. The low-temperature steel material of the C-type liquid tank body 1 can be carbon low-temperature steel or low-alloy low-temperature steel. In this invention, the C-type liquid tank body 1 is made of LIH-N low-temperature steel. It should be noted that the material of the low-temperature steel of the C-type liquid tank body 1 can be selected according to the working conditions and is not limited. The C-type liquid tank body 1 is provided with a base installation position for installing the deep well pump base 2. The base installation position is next to the liquid collection well. Its surface is ground to ensure flatness. Weld a pad 4 made of the same low-temperature steel material as the C-type liquid tank body 1 to complete the welding construction of all pre-welded parts of the C-type liquid tank body 1.

[0032] When welding the backing plate 4, a vent hole is reserved on it. Temporary protection is applied to the vent hole to prevent welding spatter, dust and other particles from entering the hole. The vent hole is not welded and sealed during the construction of the C-type liquid tank body 1. The temporary protection can be achieved by applying a sticker to the vent hole. After the C-type liquid tank body 1 is completed, the temporary protection is removed, and then the bolts and nuts are tightened before electric welding.

[0033] In the above steps, only the welding of the pad plate 4 and other pre-welded parts of the tank is completed. All other outfitting components on the C-type liquid tank body 1, except for the pre-welded pad plate 4, are not directly welded to the tank base material before the tank body heat treatment. All subsequent outfitting components are welded to the corresponding pad plate 4 after the tank body heat treatment is completed. The pre-welded fit between the pad plate 4 and the tank base material provides a stable welding carrier for the subsequent installation of the deep well pump base 2, and avoids direct welding action on the tank base material, preventing stress concentration caused by multiple welding operations. Simultaneously, the reserved vent holes and temporary protection ensure gas flow inside the tank, preventing structural deformation caused by abnormal pressure inside the tank during construction.

[0034] Overall stress relief heat treatment of the tank body: The C-type liquid tank body 1, which has completed the pre-welding construction, is heat treated to eliminate the residual stress after the welding construction of the C-type liquid tank body 1. After the heat treatment is completed, the C-type liquid tank body 1 is subjected to non-destructive testing to confirm its quality. It should be noted that the prefabrication of the deep well pump base 2 and the pre-welding and heat treatment of the C-type liquid tank body 1 are parallel processes.

[0035] The pre-welded C-type liquid tank body 1 is hoisted into the heat treatment furnace. The heat treatment of the C-type liquid tank body 1 includes the entire process of heating, holding, and air cooling in the furnace. The heat treatment process parameters meet the welding process specifications and material certification requirements of the low-temperature steel tank body of the C-type liquid tank body 1. During the heating stage, the temperature control system in the heat treatment furnace is linked with the temperature measuring elements of each part of the tank body to raise the furnace temperature to the set temperature for stress relief of low-temperature steel at a uniform heating rate, so as to avoid the tank body from undergoing temperature deformation due to excessive local heating. During the holding stage, the set temperature is maintained for a specified time to fully eliminate the residual stress generated during the welding process of the tank body and restore the toughness of the base material. After the holding is completed, the heating system is turned off and the tank body is allowed to air cool naturally to room temperature with the furnace to avoid the generation of secondary stress caused by forced cooling.

[0036] After the C-type liquid tank body 1 is cooled to room temperature, it is hoisted out of the heat treatment furnace. Non-destructive testing methods such as X-ray inspection and ultrasonic testing are used to conduct a comprehensive inspection of the weld joints and base material surface of the C-type liquid tank body 1. It is confirmed that there are no welding defects in the tank body and no deformation or cracks in the base material. Only after the quality is qualified can it enter the next process. In this step, the temperature control system of the heat treatment furnace works in conjunction with the temperature measuring element of the tank body to take into account the structural characteristics of the tank body and ensure the uniformity of stress relief heat treatment of the C-type liquid tank body 1. It effectively eliminates welding residual stress. In addition, since the deep well pump base 2 is not put into the furnace with the tank body, the influence of high temperature on the geometric accuracy of the base is completely avoided.

[0037] After heat treatment, the base is assembled: After the heat treatment of the C-type liquid tank body 1 is completed, the base installation site is cleaned, positioned and leveled. After verifying the installation benchmark, the prefabricated qualified deep well pump base 2 is hoisted to the designated installation position. Specifically, the base installation site of the C-type liquid tank body 1 after heat treatment is thoroughly cleaned to remove oxide scale, dust, oil and other impurities from the surface of the site.

[0038] The deep well pump base 2 is positioned using measuring tools, and its levelness and coaxiality are monitored in real time during the adjustment process. Specifically, a level and leveling device are used to position and level the surface of the pad 4, and the installation reference of the pad 4 is checked to ensure that the levelness of the surface of the pad 4 meets the base installation requirements. The levelness and coaxiality of the deep well pump base 2 are adjusted to meet the assembly requirements to ensure that the installation and fitting accuracy of the deep well pump base 2 and the deep well pump 3 are matched. After positioning, the deep well pump base 2 is welded and fixed to the pad 4, and the weld quality is inspected.

[0039] After the deep well pump base 2 is positioned, a special welding process for dissimilar materials such as stainless steel and low-temperature steel is used to weld and fix the lower end connecting structure of the deep well pump base 2 to the pad 4. During the welding process, the welding heat input is controlled to avoid deformation of the pad 4 or deviation of the base accuracy due to excessive welding temperature, so as to ensure the fusion quality and forming effect of the weld. The weld quality between the deep well pump base 2 and the pad 4 is inspected using non-destructive testing methods, such as penetrant testing or ultrasonic testing, which can be selected according to the working conditions without limitation. The weld is confirmed to be free of defects such as porosity, slag inclusion, and lack of fusion to ensure that the weld quality meets the requirements of the welding process specification.

[0040] After the above process is completed, the subsequent construction procedures of the C-type liquid tank body 1 are carried out, including the installation of the remaining outfitting components and piping systems, hydrostatic testing, insulation construction, and cleaning and sealing. Specifically, the remaining outfitting components on the C-type liquid tank body 1 are welded one by one to the corresponding pads 4 to complete the laying and connection of the piping system inside the C-type liquid tank body 1; then, the C-type liquid tank body 1 is subjected to an overall hydrostatic test to test the sealing performance and structural strength of the C-type liquid tank body 1; after the hydrostatic test is passed, insulation construction is carried out inside and outside the C-type liquid tank body 1 to ensure the low-temperature insulation performance of the C-type liquid tank body 1; finally, the inside of the C-type liquid tank body 1 is cleaned and the openings such as manholes and flanges are sealed until the overall construction of the C-type liquid tank body 1 is completed.

[0041] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0042] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes that element.

[0043] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base, characterized in that: Includes the following steps: S1. Prefabricated Deep Well Pump Base: The deep well pump base is fabricated, and the flanges and connecting structures on the base are machined according to the installation accuracy requirements of the deep well pump. After passing accuracy testing, it is ready for use. S2. Pre-welding and Heat Treatment of the C-Type Liquid Tank Body: A suitable C-type liquid tank body is used. The C-type liquid tank body has a corresponding base installation position for installing the deep well pump base. A low-temperature steel pad of the same material as the C-type liquid tank body is welded on. All pre-welded parts of the C-type liquid tank body are welded. The pre-welded C-type liquid tank body is then subjected to further processing. Heat treatment is performed to eliminate residual stress after welding of the C-type liquid tank body. After heat treatment, non-destructive testing is performed on the C-type liquid tank body to confirm its quality is qualified. S3, Base assembly and fixing: After the heat treatment of the C-type liquid tank body is completed, the base installation site is cleaned, positioned and leveled. After verifying the installation benchmark, the prefabricated qualified deep well pump base is hoisted to the designated installation position. The levelness and coaxiality of the deep well pump base are adjusted to meet the assembly requirements. After positioning, the deep well pump base is welded and fixed to the pad, and the weld quality is inspected.

2. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: In step S1, after the deep well pump base is machined, it is subjected to surface treatment. The machining accuracy must ensure that the flatness of the flange surface and the coaxiality of the stop of the deep well pump base meet the direct assembly requirements of the deep well pump.

3. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: In step S2, when welding the pad, a vent hole is reserved on it, and the vent hole is temporarily protected. The vent hole is not welded and sealed during the construction of the C-type liquid tank body. The temporary protection is removed after the construction of the C-type liquid tank body is completed.

4. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: Except for the pre-welded backing plate, all other outfitting components on the main body of the C-type liquid tank are not directly welded to the tank base material before the tank body is heat treated.

5. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: In step S3, the heat treatment of the C-type liquid tank body includes the entire process of furnace heating, heat preservation and air cooling of the C-type liquid tank body. The heat treatment process parameters meet the welding process specifications and material certification requirements of the low-temperature steel tank body of the C-type liquid tank body.

6. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: In step S4, the deep well pump base is positioned using a measuring tool, and its levelness and coaxiality are monitored in real time during the adjustment of the deep well pump base to ensure that the installation and fitting accuracy of the deep well pump base and the deep well pump are matched.

7. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: In step S4, the weld quality between the deep well pump base and the pad is inspected using a non-destructive testing method to ensure that the weld quality meets the requirements of the welding process specifications.

8. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: After step S4 is completed, the subsequent construction procedures of the C-type liquid tank body are carried out, including the installation of other outfitting components and piping systems, water pressure testing, insulation construction and cleaning and sealing, until the overall construction of the C-type liquid tank body is completed.

9. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: The main body of the C-type liquid tank is made of cryogenic steel; the base of the deep well pump is made of stainless steel.

10. The heat-free, deformation-resistant construction process for a C-type liquid tank deep well pump base according to claim 1, characterized in that: Step S1 and step S2 are parallel processes.

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